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Have Passive Preamps Finally Come of Age?

Back in the late 90s (eons ago) I tried a variety of passive preamps (PPs). The most musical was an autoformer, but back then my system was not balanced. For the last decade I have been using active preamps, both tube and solid state, but finding a quality balanced preamp under $4K is damn near impossible. Enter the Parasound P5 (2.1), which in addition to having balanced I/Os, it has a separate bass management circuit (MSRP $1095), and I was hoping it would provide better control over the built in class D plates incorporated into my 2 SVS powered subs, whose volume controls are STUPIDLY sensitive: when barely cracked from zero they overwhelm. Alas, no bueno. 

Recently i watched a PS Audio YT video that was emphatic about NOT connecting powered subs with interconnects; instead he recommends speaker cables piggybacked off the main systems amp/s. I had a spare set of DIY flat copper cables, and was shocked how much better they sounded, but doing so did not change the  volume control problem and unfortunately this id not bypass the SVS amps whose class D chips are now ancient. Thinking there could be an impedance problem led me to revisit PPs.

I sold my P5 and was using the XLR outs from my Oppo 105 (upgraded power supply and IEC/wiring to the power supply) direct to my Emerald Physics 100.2SEs (class D). The noise floor dropped tremendously, allowing me a much better view into the music. My Core Power Technologies 1800 PLC had more than a little to do with this, but...  

Days of PP research later, I came across LDRs, which seem like the ultimate PP option, but XLR versions are ~ $2K and up, with the Tortuga coming in at $2700, seems like a true SOTA bargain, just not in my current budget. Scouring the' for sale' sites I came across a Hattor XLR (MSRP $995) which was in my price range. Hattor's www had links to 2 reviews both were extremely positive: one used it in combination with a class D amp. Bingo! I snapped it up.

It arrived late yesterday, although Hattor's www pictures look awesome, they do not compare to seeing and touching it. The metal carrying case was an indication of the designer's dedication. This is an etremely well made piece of kit, but how does it sound? Alas it came with no manual and Hattor's site does not have a PDF. How hard can it be to hook up? Well, after a couple scary minutes, I discovered that it would not light up until I connected the 105. 

Stone cold, the first thing that shocked me was a further reduction in noise floor and an incredibly wide and deep sound stage, but as can be expected, it was dry. Fingers crossed, in about a half hour I began to be rewarded with texture as well. Tis only got better as the night wore on

I hope somebody chimes in with their Tortuga experience, or any other high quality PP information.that goes under the reporting radar. 
tweak1
georgehifi's avatar
georgehifi
4,966 posts
 
I don’t remember which customer lent us the Lightspeed
You attack my product and you tell me to keep calm, conveniently not remembering who it was.

With a 3 foot high quality cable (which would have 300pf) in such cases you would have a roll-off that is very real world.
Then you present this BS, and then try to back peddle after I’ve shown the truth with the math.

Clearly it’s you in damage control, after all this is a Passive Preamp thread and all you present is negatives.
Stick to the active preamp threads and stop putting **** on passives at every opportunity.
celander's avatar
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celander
1,036 posts
 
This back and forth is hilarious.

Let us distill it to its simplest form.
1. atmosphere considers George’s Lightspeed unit to be a fine passive preamp device, albeit limited in its design (1 input and 1 output) and clearly not as good as what atmosphere has auditioned by way of active preamp devices (hint, hint: atmosphere’s own company’s devices.)

2. George feels butt-hurt because atmosphere views his Lightspeed passive preamp as being inferior to atmosphere’s active preamps.

3. The causal observer of this banter would conclude that:
(a) atmosphere is entitled to opine about comparisons between his company’s active preamps and George’s Lightspeed passive preamp, because the forum thread is entitled, “Have passive preamps finally come of age?” Atmosphere concludes that the answer to that question is “No,” at least with respect to the Lightspeed passive preamp.
(b) George is entitled to take the opposite view of atmosphere’s opinion, notwithstanding his disappointment in atmosphere’s conclusion.
mitch2
1,911 posts
 
@celander 
This back and forth is hilarious.
I mostly agree.  For example, what does "finally come of age" mean? 

The Hattor is simply a resistor based passive volume control, not unlike Goldpoint, Placette, and others that have come before, and not really unlike what is in Ralph's preamps except that those also provide buffering and gain. 

George wants us to believe the Lightspeed is "compatible" with most impedance and gain situations - and that may be true.  However, just because something is "compatible" doesn't mean it is the best-sounding option. 

What's missing is that this is really about what one hears in their own system.  If a listener likes the sound of a certain type of passive in their system, then that's what matters.  If they want to compare their passive with an active circuit, then they can simply connect a buffer to the passive and decide which sounds better.  There are many on this site who enjoy the sound of their passive volume controls and many others who prefer their active preamps or buffers.  There are other options such as DACs by Empirical Audio and Metrum Acoustics that adjust volume by changing the reference voltage, which does not negatively affect the signal like DACs that throw away bits of information to reduce the volume level.  This is really easy, try several options and stick with what you like best.
georgehifi's avatar
georgehifi
4,966 posts
 
If a listener likes the sound of a certain type of passive in their system, then that’s what matters. If they want to compare their passive with an active circuit, then they can simply connect a buffer to the passive and decide which sounds better. There are many on this site who enjoy the sound of their passive volume controls and many others who prefer their active preamps or buffers.
All this is so true, and I’m sure tweak1 is glad we are back on topic.

" Have Passive Preamps Finally Come of Age? "
I believe so and some, but like the active preamp, it also is going to become a dinosaur, as all the volume control duties are best done at the source so long as "bit stripping" is held in check maybe with a loudest level gain preset like Wadia and ML did, also with output stage buffers that are as good or better than most active preamps it going to be a win win, also noise floor is as low as it can get with direct source to amp connection, and only one set of interconnects.

Cheers George
mrdecibel
1,244 posts
 
Hello A’gon members. I have had my Luminous Audio Axiom, Walker Mod, 3 in, 2 out, single ended remote unit for quite a while now. Without slighting the preamp manufacturers, nor those readers who might own the preamps I have been using ( I will not name them , I will say, without a doubt, that I am much happier, without the preamps in my system. I have tried passives before, but never thought they " came of age ". Maybe it is my amp’s high gain, or my efficient speakers, but it has all come together. I suppose I am one of the few lucky ones, as I am rediscovering recordings that I thought I knew so well. Lets all just get along. Enjoy ! MrD.
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